cant enable XML-RPC.

Hi.
In trying to use my worldpress blog on my newly installed app on my iphone.
I can't get in - it says "XML-RPC service are disabled on your blog".. I have tried the guides and the seen forums in here, but without any help.. The guide on my iPhone says go to settings --> writings and then under remote publishing, check the XML-RPC protocol checkbox.. The problem is, I haven't this XML-RPC protocol checkbox on my scream.. what can I do about it? (I also checked youtube for help, and found out my scream under writings didn't look like others...